The present invention relates to assembly for the transfer of a fluid between a duct and a space between two thin sheets, i.e., for feeding of a fluid into or removal of a fluid from this space. More particularly, the present invention is related to means for creating a fluid tight seal in such apparatus.
A number of apparatuses for transferring a fluid between a duct and the space between two thin sheets are known. For example, U.S. Pat. No. Re 27,510 discloses a device in which the ends of a tubular membrane are folded around a highly elastic terminal tube 9 and pulled together under strong friction so as to be leak-proof. The patentee thus employs a conical bore 8 of a confining rim 10 in the outer casing 13 as best shown in FIG. 4 of the patent.
U.S. Pat. No. 3,712,474 teaches another such device which includes connector units 52 and 54 as best shown by FIG. 6 of the patent. In each unit, patentee includes a substantially resilient body portion 60 in a relatively less flexible cup element 62. By closely conforming the internal cup dimension to that of the body and by forming the body of a substantially resilient material, a snug fit is provided. Moreover, at least one O-ring 72 supported by the body insures a better fluid tight seal and prevents a possibility that the membrane will pull loose. Similar teachings are contained in U.S. Pat. Nos. 3,709,367 and 3,743,098.
U.S. Pat. No. 3,880,760 discloses yet another such device which includes a core cover section 2 adapted to mate with a core base section 1 with the ends of the tubular membrane therebetween. A similar structure is employed at the other end of the tubular membrane as shown by FIG. 2 of the patent. The core cover and core base sections are provided with seals 5 and 6 to seal the membrane tube 9 with the open end 7 of the blood inlet conduit within the membrane tube.
In a similar vein is U.S. Pat. No. 3,962,095 which discloses blood inlet and outlet means 26 for connection with arterial and veinous lines attached to a casing 22 using wedge section cover plates 28 which carry a seal 32. The cover plates 28 are secured to the casing by means of screws 30, the seal 32 sealing the free ends of the membrane tube 12 with the blood inlet and blood outlet means 26.
U.S. Pat. No. 4,059,530 discloses blood inlet and outlet ports in a dialyzer membrane 3 comprising a connector 30 connected to a header 32. The header 32 is located internally in the tubular membrane. A locking disc 33 locks the membrane 3 against one wall of the header 32. The header is provided with internal chambers 35 communicating with the interior of the tubular membrane 3.
Other similar devices are shown in U.S. Pat. No. 3,963,621, British Pat. No. 1,417,446 and British Pat. No. 1,433,512. U.S. Pat. No. 3,963,621 merely states that a tube 18 communicates conventionally with the end 20 of a membrane 16. FIG. 3 of British Pat. No. 1,433,512 shows a membrane tube 2 pleated around a rigid connecting plug 38. Medical plaster 41 is applied around the membrane tube and the tube is secured by means of two knotted cords 42 and 43 in the annular grooves 39 and 40 of the plug. British Pat. No. 1,417,446 merely discloses that the core 1 includes an opening in which a sleeve 31 fits so that the blood tube 12 can be connected to the membrane tube 2.
While some of these known constructions operate in a relatively satisfactory manner, each is still subject to certain disadvantages. Among other things, certain of these constructions contain a large number of parts rendering assembly more difficult and producing a number of sealing problems. It is thus an object of the present invention to provide a construction which is simple to manufacture and assemble and which produces a fluid tight seal.